reverse_view/detail/value_at_impl.hpp

0001 /*=============================================================================
0002     Copyright (c) 2009 Christopher Schmidt
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007
0008 #ifndef BOOST_FUSION_VIEW_REVERSE_VIEW_DETAIL_VALUE_AT_IMPL_HPP
0009 #define BOOST_FUSION_VIEW_REVERSE_VIEW_DETAIL_VALUE_AT_IMPL_HPP
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/fusion/sequence/intrinsic/value_at.hpp>
0013 #include <boost/mpl/minus.hpp>
0014 #include <boost/mpl/int.hpp>
0015
0016 namespace boost { namespace fusion { namespace extension
0017 {
0018     template <typename>
0019     struct value_at_impl;
0020
0021     template <>
0022     struct value_at_impl<reverse_view_tag>
0023     {
0024         template <typename Seq, typename N>
0025         struct apply
0026           : result_of::value_at<
0027                 typename Seq::seq_type
0028               , mpl::minus<typename Seq::size, mpl::int_<1>, N>
0029             >
0030         {};
0031     };
0032 }}}
0033
0034 #endif